The paper presents a program very useful for calculating the water and steam proprieties. The program , elaborate in programming language Borland Pascal has 4 procedures for superheated , saturated water and steam. Equations assure the computation of thermodynamic values with maximum deviations: ± 0,05 % for constant volume, ±1kJ/kg for enthalpy and ±0,0010kJ/kgK for entropy. Accuracy of the equations and consistency along the region boundaries are more than sufficient for engineering application.